Data processing apparatus



Jan. 16, 1968 M G, BlENHOFF ET AL 3,364,471

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DATA PROCESSING APPARATUS Filed May 23, 1963 15 Sheets-Sheet 3 To GATES 1 7 10 SIGNAL FROM LOGtC N @MESZ 065 R 40a j DiLAv CLOCK il-*p* PULSE Op L QEGlSTER DLO- DME @WLAN 4m 426 r@ zl A24 fAosc; Tui TEL F Ds h w TLEORTLE 1A TELDRTEL C' LAN E RECv$TER DE01 DElS /fmwf M7 A TTORNEY Jan. 16, 1968 M. G. BLENHOFF ET AL 3,364,471

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DATA PROCESSING APPARATUS 15 Sheets-Sheet 12 Filed May 23 1963 mad NO JD Jan. 16, 1968 M Q BiL-:NHOFF ET AL 3,364,471

DATA PROCESS ING APPARATUS 13 Sheets-Sheet 13 Filed May 23 19625 S GES .ao EL3 5m@ 0mm A NMN md 5MP PmC. EUL .Ow En; dau EE ,n SUL UHU EL 9E@ EL3 QQ EL3 SEQ EL3 DEQ EL3 n@ EL3 nknmNV/ NNml/Y//Omw d********,****i 9.5 ZUG Qs z5 z5 H? z5 HG QS UNG @s au E EU d lo md w md 0.6 md E@ n.6 N N AO am mj@ 7&0 Oud IAQ d Hw??? IMMWV, No@ Q m wa., mj@ EMM 1 V .u .u MOQNEZM@ @z mijn VO 00m, GOS mov mow; 5MP EE @p6 E E dw EUL .Gau S dw SUL 1G EE w 6E@ EL3 Bc EL3 acca EL3 0:.:5 EL3 EEQ EL3 ,Egan EL3 @E fmlfmm//Qm/Qm/A/ mowom @oom T2, T LU a? L@ :MQ Q5 z5 HG 5 EQ ha uw S, 9G E Ut AWS EL? @d m3 En v o N n.5 N I z5 A A H H om om v n N vom A lil a m N OIQmZm@ Z Q Y l w U2 wsu O NN oom V605 ww QM United States Patent O 3,364,471 DATA PROCESSING APPARATUS Milton G. Bienholf and Edward J. Schneberger, Canoga Park, Calif., assignors, by mesne assignments, to The Bunker-Ramo Corporation, Stamford, Conn., a corporation of Delaware Filed May 23, 1963, Ser. No. 282,706 1S Claims. (Cl. S40-172.5)

This invention relates generally to data processing apparatus and more particularly to means for reducing the processing time required to compare a first block of data words with a test word or a second block of words.

In order to perform an operation with conventional computers of the type wherein a sequence of words which are stored in the computer memory are compared to a word held outside of the memory, or two word sequences held in the memory are compared with one another, or where words in a sequence in the memory itself are compared with one another, a rather complicated program has to be written which effectively requires an instruction for practically every step of the operation to be performed. This makes for a rather cumbersome program, and slows the operation of the computer, since it is necessary to read the instruction after each step before performing in respouse thereto.

An object of this invention is the provision of a computer wherein operations of the type specified may be achieved without the necessity for providing a separate instruction for substantially every step of the operation.

Another object of this invention is the provision of a computer having a structural arrangement which enables the specified operations to be carried out in response to a single command set.

Yet another object of the present invention is the provision of a computer having structural arrangements such that the specified operations may bc cllectuated simply and rapidly.

Brieliy, the invention herein is based on the recognition that in the performance of certain operations by data processing apparatus, considerable processing time can be saved by minimizing the number of memory accesses normally required to perform such operation. More particularly, where each of a plurality of data words stored in memory is to be sequentially compared with a test word or a second plurality of data words, it is recognized that processing time can be saved by accessing only the requisite data words from memory. That is, in response to a single instruction word, the requisite data words are automatically sequentially accessed and compared without requiring that a plurality of instruction words, which together conventionally comprise a subroutine, be accessed.

In a preferred embodiment of the invention a stored logic computer of a type which has been described and shown in an application for a Stored Logic Computer by Edward J. Schneberger et al., Ser. No. 164,660, filed Jan. 8, 1962, and assigned to a common assignee is extended to include the present invention. The structural arrangement of this computer is such that the necessary functions of reading out of the computer memory, restoring the information read therefrom, and transferring necessary data read from the memory to registers for the purpose of comparison, and also the function of obtaining the address sequence data in the memory is ail carried out in response to a single instruction set. The computer, in response to the instruction set, which is here termed a logand, continues the operation indicated of sequentially comparing words from the memory either with other memory words or with an external word, until the conditions specified within the instruction set is met.

The novel features that are considered characteristic of this invention are set forth with particularity in the ICC appended claims. The invention itself, both as to its organization and method of operation. as well as additional objects and advantages thereof, will best be understood from the following description when read in connection with the accompanying drawings, in which:

FIGURE 1 is a block diagram of a stored logic computer of the type with which this invention may be practiced;

FIGS. 2A, 2B, and 2C are logic block diagrams showing how input signals for the state counter of the computer, as shown in FIG. 2D are derived:

FIG. 2D is a logic block diagram of the state counter which is used in the computer;

FIG. 3 is a block diagram of the computer input-output circuits;

FIG. 4 is a block diagram of the timing control register used to time input and output data flow;

FIG. 5 is a block diagram of a register used to designate the proper input or output channel for the computer;

FIG. 6 is a block diagram of a llip-liop and its associated logic circuit which is employed for indicating thc availability of the T register of the computer;

FIG. 7 is a block diagram of circuits used for control of the input of a word to the computcr of thc derivation of an output therefrom;

FIG. 8 is a block diagram of flip-flops and logic required for interrupt routines;

FIG. 9 is a block diagram showing the memory rend and write circuits which operate in response to either L or M register address;

FIG. 10 is a block diagram of a delay llip-ilop used to make up a register;

FIG. 11 is a block diagram of a logic control transfer from the L to the E register and from the E to the L register;

FIG. 12 is a schematic diagram of logic means for generating a stroke pulse;

FIGS. 12A, 12B and 12C are diagrams exemplifying logand formats;

FIGS. 13A, 13B and 13C are diagrams exemplifying logand formats of a type which are used with this invention;

FIG. 14 shows a block diagram for achieving a complementing operation in the A register;

FIG. 15 is a block diagram showing in accordance with this invention an arrangement for indicating the occurrence of two predetermined conditions;

FIG. 16 is a block diagram of an arrangement in aecordance with this invention for indicating the occurrence of two other predetermined conditions; and

FIGS. 17, 18 and 19 are schematic diagrams showing the logic for collecting signals for respectiveiy initiating table look-up, match. and sort operations.

For the purpose of understanding this invention it is necessary to understand the operation of a computer of the type referred to in the foregoing application for patent. Accordingly, there follows a description of the computer which is extracted from that appiication for patent. The logic instructions for the computer which may also be designated as logands are stored in the memory. FIG. l is a block diagram of such a stored logis computer. The machine contains a random access memory 10, exemplified as a magnetic core storage memory. Vluto the memory there may be entered, in advance of the machine functioning to process data, logic instluclions or logands which are required to instruct the remainder of the machine how to process data which is entered therein. These logands may consist by way of example, o1" l5 bits. Groups of these 15 hit logands for achieving a dcsired set of basic operations are designated as lograms,

In addition to the core memory, the stored logic nuichiue includes six flip-flop registers, each capable of sloring l5 bits, by way of example. These registers are designated as an L-register 12, an E-register 14, an lvl-register 16, a P-register 18, an ,Ai-register 2t), and a T-register Z2. In addition to the registers, the computer contains a l5- bit parallel full-adder 24 and a t5-bit parallel half-adder 26. In addition. the machine has a power supply 27 and a power supply monitor 29, a computer control and maintenance Switchboard 28, a control counter 30, a state counter' 32, clock-pulse generating circuits 34, and various control circuits for operation of the machine which will be discussed as this description progresses.

The E-register is used principally for holding infortuntion read from and/or written into the memory. The E- register also accepts the transfer of IS-bit operands from the L-register. the P-rcgister, the A-register, the T-registcr. and the M-register via the hall-adder 26. Transfers to the E-register from the various other registers are shown by the lines ending in arrows from the respecitve reg'sters. which arrows terminate at the lil-register. The logic and gating circuirty required for ellectuating a transfer to the E-register is represented by rectangles in the path of these lines. Thus, the transfer of bits of data from the L- rcgister to the E-registcr is under control of TLF. circuits 36. The transfer from the T-register to the E-register is Linder control ol TTE circuits 38. The transfer from the A-egister to the E-register is under control of TAE circuits 40. The transfer from the P-register to the :li-register requires operation of circuits TPE 42. The transfer from the hr1-register via the half-adder 26 to the E-rcgister requires the operation of CME circuits 44. ln addition, the egister circulates its contests via control and logic circuits TEE 46.

[n addition, the E-regisler can receive data from inputoutput equipment 48 through any one nl three cables ABC via input-output amplihcrs 50. The se' e ton cf cable A is under control ol (IAE logic circuits EZ and gates 53. The selection of cable B is under control of CIRE logic circuits 54 and gates 55. The selection cf cable C is under control of CICE logic circuits 56 and gates 57. The E-register is the only register that receives information directly from the core memory and f'om which information can be written directly into the memorv.

The L-register 12 is used to hold a logand while it is being interpreted by the logic circuits of the computer. The L-register receives its input from the E-register over gating and logic circuits TEL 58. The logand signals in the L-register are the logic signals which in conjunction with other sequencing signals. whose derivation is to he described. direct the operation ot' the computer. The loworder sis bits of the L-rcgister may be employed to address memory locations l) through 63 of the magnetic-core memory. This portion of the magnetic-core memory is designated as a scratch-pad memory. 'The scratch-pad section of the memory provides a temporary storage for intermediate results of commutation. or logands. The L- register circulates its contents, using the TLL 6() gating and logic circuits. The L-register can address the core memory I() through addressing and driving circuits. designated as X and Y selcct-and-write circuits 62. 'l he data entered into the core storage memory 10 is that contained in the E-register 14. Thus, when the memory is addressed by the L-register for the purpose of writing, the data entered into the scratch-pad memory is that data which is in the E-register at the time.

The core storage memory 10 is of a type well known in the art, which consists of a plurality of core planes. in each of which core plane there are magnetic cores disposed in columns and rows. The crlumns and rows of cores are aligned so that a row coil is coupled to thc` same row of cores in each core plane. A ccltnnn coil is coupled to the sante column of cores in each cwe naine. The row and column coils are commonly rclcf: l to as X and Y coils. Selection of a corrcspondingly yorttionctl cote in cach core plane for the purpose of being driven lll toward one of its two states of magnetic remanencc is achieved by applying current to the X and Y coils coupled to these cores. There i; a separate winding for each core plane which is coupled to every coil in the core plane. This is known as an inhibit winding. Thus: of the cores which it is desired to maintain in the state of remanence opposite to which they would be driven by the excitation of the X and Y cores may be so maintained by simultaneously applyi tg an i.iliilit-cttrrenl drive to the inhibit coil for that core plane. The l regster output is applied to inhibit circuits 64, which are opel'- ated in conjunction with the X und Y selcct-and-tvrite circuits for entering or writing into the core storage memory the contents of the E-rcgister iti either a lrcation in the scratch-pad memory, whose address is provided by the ic-register. or in any location in the memory in an address which is provided by thc Ivi-r gister.

The output of the core storage mcn'tory, consisting ot` a hit of data obtained from each core which is interrogated, is applied to the reading amplifiers (r3. .he outputs of the reading ampliters are entered into the l-rcgister through gates under control of strobing pulses provided by strobing circuitry 67. This insures that thc output of the cores is read at a time when false reading signals are minimied.

The lvl-register I6 is used principally for addressing any one of the locations in the core memory. lt operates in conjunction with the half-adder 26 to increment au address in the lvl-register. when so ordered, in order to provide the address otv the next logand to be derived from the memory for execution. The lvl-register output is always applied to the half-adder 26. Vvhether or not the contents of the half-adder are incremented is determined by DMSO control logic circuits 68. The details of the operation of the DMG() logic circuits will be provided subsequently herein. The hall-adder contents are returned to the lvl-register through logic and gating circuits. designated as TMM 70. The M-register can also receive the contents of the E-register over the Tllvl logic and gating eircuis 72. The lvl-register can receive the contents of the A--r gister over the TAM logic and gating circuits 7-l. The P-register may enter its contents into the lvl-register over the TPM logic and gating circuits 76.

It was pointed out that the lvl-register, by controlling the X and Y Select-and-vvrite circuits. can provide the address ol any location in the core storage memory for the purpose ot either reading or writing. tty means ot the transfer circuitry just described the conents of either the A-register, the P-register, or the E-register. may be substituted into the ltd-register in place ot the contents of the M-register. Thus` the core memory may effectively be addressed by an address within the E A, or P-registers, as well as an address in the hit-register. Furthermore. by transferring the contents of the L or T-rcgister through one of the other registers into the hit-regidor. the memory can be addressed from any one of the r i the computer.

llf desired, the address in the lvI-regi.lter can be transferred to one of the other registers to be held there until the operations specified by the logand read from the substituted address have been carried out, at which time the M-register address can be translerred back.

There is no direct transfer out ot data from the M- register. This always occurs thru the ha'ttadder, i.e from M-register to halt-adder to other register. "This facility is provided by the control-and-ating circuitry F 44, whereby the output of the half-adder may be enter d into the i-register. The output of the half-adder may be entered into the P-register thru control-ant'l-gating circuitry Civil tilt. The lvter contents can he entered into the A-regiser via the half-adder by the ctuttrol-andding circuitry Cl'tA S2.

Comidctirtgt, next, the P-fc'fister. its contents arc t'irculttctl hy TP!) controlnnd` titty -l. 'l he rontcnts ol thc l"-rcgistcr are t nio thc r-icgister over TPA control-and-gating circuitry 86. The contents of the P-register may be entered into the E-register over the TPE control-and-gating circuitry 40. When required, the contents of the P-register may be shifted right under control of the gating-and-control circuitry 90. The contents of the P-register may be shifted left under control of the gating-and-control circuitry TPF 92.

The contents of the A-register may be entered into the E-register via TAE gating-and-control circuitry 40. The contents of the A-register may be entered into the T- register via TAT control-and-gating circuitry 96. The contents of the A-register may be shifted right under TAR control-and-gating circuitry 98. The contents of the A- register may be shifted left under TAF control-and-gating circuitry 100. The A-register, which may also be designated as an arithmetic register, is used primarily to hold the results of arithmetic operations performed by the adder 24 and some logic operations. The A-register receives its principal inputs from the full adder 24. It may, however, receive its input from other registers, as indicated. The A-register may also transfer its contents into the P-registcr under control of the TAP control-and-logic circuits 104. The A-register and the P-register may be shifted left or right, either alone or while coupled together. Thus, the P-register may be used as an extension of the A-register for shift multiply-and-divide operations, when required.

The T-register is used principally for transferring data from the computer to the output devices. It may be used for transmission of output, while the rest of the computer proceeds independently. It may accept data from the E- rcgister thru the TET control-and-logic circuits 108. It may accept data from the A-register thru the TAT control-andlogie circuits 96. Data from the T-register may be circulated thru the TTT control-and-logic circuits 106. Data from the T-register may be transferred to the E- register under control of TTE control-and-logic circuit 33. Data from the T--register may be transferred to the A- register under control of the TTA control-aud-logic circuits 110. input to the T-register from the input-output equipment occurs via the inputcutput ampliers through gates 112, which also require control signals from CIAT control circuitry 114, or through gates 116, controlled by CIBT control circuitry 118. The gates 112 admit data from an A cable, and the gates 116 admit data from the B cabie.

The L, E, M, P, A, and T registers each contains l5 Hip-flop circuits, known as delay flip-flop circuits since the output in response to an input signal does not occur until the clock pulse succeeding the one assisting in driving the iiip-ilop. These tiip-iiop outputs are designated by the letter D followed by the letter designating the register, followed by a number indicating the position in the register followed by an N or a "C." N designates that the output is true or normal and C false or complement. Thus DL12N indicates that the twelfth flip-hop of the L-register has a true output. The registers, unless instructed otherwise by a logand, circulate their contents on every clock pulse. Each one of the T or C transfer logic circuits effectively constitutes 15 coincidence gates having the l5 true sides of the delay ip-tiops as one input and a transfer signal as a second input. The transfer signal is usually provided by an amplifier, called a control amplifier, which is driven by the logical output of gates which decode the logand in the L-register. Clock signals time the entry of data into the registers.

The very rst logand entry into the memory may be by setting switches which are furnished with the computer-control-and-maintenance switchboard 28. The setting of these switches is entered via the TSE gating and control circuits 120 into the E-register. This first instruction is then transferred into the L-register, which, may, in response thereto, control the entry of data into the core storage from the input-output equipment. The instructions or lograms entered into the core storage may thereafter be used for operating the computer.

The control counter 30 is a three-ilp-ilop counter and therefore may be set in any one of eight different states. It is used for manual control of computer operation from the maintenance panel. The states of interest, in accordance with this invention are the ones which occur when the computer is running. When the three stages of the control counter are in their true states, their respective outputs may be designated as FCOIN, FCOZN and FCOSN. By actuating a switch on the switchboard 28 for operating the computer automatically, the control counter is operated to the state in which all three stages signify their true outputs.

State counter 32 consists of three flip-Hop stages; seven distinct control states for the computer are defined by the outputs from this state counter. FIGURE 2D is a block diagram showing the three flip-fiop stages, respeciively FSOl, F502, and FSO3 for the state counter and the logic which sets these fiip-op circuits in its various states. FIGURES 2A, 2B, and 2C are logic diagrams which are used to define some of the input terms in the logic .shown in FIGURE 2D. These diagrams illustrate how complex logic control signals are obtained from simple logic signals and are used to simplify the logic required to be shown in FIGURE 2D to actuate the Hip-flop stages. Reference is now made to FIGURE 2A, wherein an AND gate provides an output signal, which is designated by GAO14, when all of its inputs are simultaneously present. These inputs are the complement outputs of the first four flip-flop stages of the L-registcr. These are designated as DLOlC, DLOZC, DLO3C, and DLO4C. The letter C designates that the output is the complement, or false output. The letter N designates that the output is true, or the normal output.

An AND gate 132 provides an output signal which is designated by GAO33 when both of its inputs, respectively DL14C and DL10N, are present. These are taken from the fourteenth and tenth flip-flops in the L-register. GAO14 and GAO33 exemplify logand decoding. An output signal, designated as GAO50, is derived from an AND gate 134 when its two inputs are simultaneously present. These two inputs are FCOIN and FCO3N. These are the respective true outputs derived from the first and third stages of the control counter. An output designated as GAOSI is derived from an AND gate 136 in the presence of its two inputs. These two inputs are respectively FCOIN and FSOSC. These are the true outputs of the first stage of the control counter and the complement output of the third stage of the state counter.

Referring now to FIGURE 2B, an AND gate 138 provides an output signal designated by CWIAN in the presence of the three inputs, respectively FSOIC, FSO2N, and GAOSl. FSOIC is the complement output of the first stage of the state counter, and FSOZN is the true output of the second stage of the state counter. The GAOSI signal is derived from AND gate 136, shown in FIGURE 2A. An AND gate 140 supplies an output designated as CRHSN in the presence of the inputs GAOS, derived from AND gate 134 shown in FIGURE 2A, FSOZC, the complement output of the second stage of the state counter, and DL15C, which is the complement output of the fteenth stage of the L-register. An AND gate 142 provides an output designated by CWLAN in the presence of inputs GAOSI, FSOZN, and FSOIN.

In FIGURE 2C, the logic required to drive a hip-hop designated as FLOO to provide either an output FLOON or FLOOC is shown. An output is derived from an AND gate 144 in the simultaneous presence of inputs GAOSU, FSOZC, and DLlSC. The output of AND gate 144 is applied to an AND gate 146. The output of the AND gate 146 is applied to the ti'rp-op FLOO through an OR gate 148. AND gate 146 requires the simultaneous presence of the output of AND gate 144, as well as inputs DLOSC, DLISC, DL14C, and DL13C, and FLOOC,

which is the complement output of the FLOO flipflop.

An AND gate 150 can provide an output to a succeed* ing AND gate 152 in the simultaneous presence of inputs GAOSL FSOIN, and FSOZN. AND gate 152 can drive Jtlip-liop FL through 0R gate 148 to provide a normal output in the simultaneous presence of the output of AND gate 150, as well as complement outputs from E-register tiip-iiop stages DEllC, DE13C, and DEISC. FLO() llip-llop is driven to provide a complement output FLO0C in response to the output of an AND gate 154, which drives the lliptlop through an 0R gate 156. The AND gute requires simultaneous inputs, GAOSI, F5010 and FSOZC.

FLO() muy also be driven to provide a complementary output by an alternative logic network. This includes the output of an AND gate 158 having as its input FCOIN and F5030 This AND gate output is applied to a following AND gute 160. An AND gate 162 provides an output in the presence of inputs GAOSI, FSOIC, FSOZN, and DLISC. lts output drives a succeeding AND gate 164, which can provide an output to the AND gate 160 in the simultaneous presence of inputs DL14 and DL10. AND gate 160 can therefore drive the FL00 flip-flop to its complement output state in the simultaneous presence of the outputs of AND gates 158, 164, DLOSN, DLO4C, DLOSIC, und DA01N. These outputs are respectively derived from the L-register fifth stage, L-register fourth state. I.regiser third state, and A-registcr first stage.

Referring now to FIGURE 2D, the logic for driving the state counter flip-flops F501, F502, and F503 may now he understood. The ip-op F501 is driven to provide FS01N output in response to CWIAN signals (derived from AND gate 138), which are applied to the flipilop through an 0R gate 166. An AND gate 168 provides an output in response to the presence at its inputs of signals CAOS() and FSOZN. An AND gate 170 can provide an output in the presence of simultaneous inputs DL13N and FLO0N. The AND gates 168 and 17() drive a succeeding AND gate 172, which can drive ip-flop F501 to provide un FSOIN Output.

F501 flip-flop is driven to provide an FS01C output by the signals derived from either an AND gate 174 or an AND gate 176, which are applied to the flip-Hop through an 0R gate 178. AND gate 174 can provide an output in response to a CWLAN input and a DE09N input. AND gate 176 can provide an output in response to a CRHSN input and an FS01N input.

The second stage of the state counter, namely, F802 [lip-flop, can be driven to provide an FSOZN output in response to the output of an AND gate 180, or an AND gate 182, or an AND gate 184, or an AND gate 186, or an AND gate 188. These AND gates are all connected to an 0R gate 190, the output of which drives the ipflop to its normal or true state. AND gate 180 requires the simultaneous presence at its input of signals GAOSI, FSOIN, and FSOZC. AND gate 182 requires the simultaneous presence at its input of signals CRHSN, DLOIC. AND gate 184 requires the simultaneous presence at its input of signals GA051, FSOlC, and FS02C. AND gate 136 requires the simultaneous presence at its input of signals GAOSO, CRHSN, FSOZC, and DLISN. AND gate 188 provides an output in response to an input consisting of signals GA014 and the output of an AND gate 192. The AND gate 192 provides an output when there are simultaneously present at its inputs the signals GAOS, FSOZC, DLC, and GAO33.

The F802 flip-flop is driven to provide a complement output (FSOZC) by the output of an AND gate 194. This AND gate provides an output in the simultaneous presence 0f signals FCOIN, FSOZN.

The third stage of the state counter, Hip-flop F503, is actuated to provide an FS03N output in response to either u CWIAN signal, which is applied to it through an 0R gute 196, or to the output of an AND gate 198. AND gute 198 provides an output in the simultaneous presence 8 of signals CWLAN and DEO9C. The latter signal is the complement output of. the ninth llip-liop in the E register. Flip-flop FS03 is driven to its complement state in response to the output of an AND gate 198. This AND gate provides an output in the simultaneous presence of signals CAOS() land FSOZN.

Also shown on FIGURE 2D is a VETTCH diagram for the counter. The various count states of the counter are designated by binary numbers t through 111. lnstead of referring hereafter to these counter states by their numerical count condition, they are referred to bv letters which are associated with the number in the box. Thus. 000 represents the Rl state, 001 the RL state, tilt) the Wl state, O11 the Wl.. state, 100 the HC state, ttl] the RP state, and llt) and 111 the WP state. When combined with GAOSI the Wl signal becomes CWIAN. The WL signal becomes CWLAN.

To interpret the VEITCH diagram, regard the HC state (100), directly below the box in which the letters HC appear, are found F503. Above, to the left and to the right of. the box in which HC appears, it will be seen that the letters F801 and F502 do not appear.

The states which the Hip-flops assume in order to represent HC may be derived from the VEITCH diagram and also may be represented by a logical equation as follows:

Taking another example, note RL on the diagram. Looking to the left, to the right and below the RL box, no state counter flip-flop designations are found. Looking above this box, F501 may be found. Thus, the states of the state counter stages may be represented by the logical equation:

RLZFSOlN-FSOZC-FSOiC lt is believed that with the 'foregoing exumpics, the use of the diagram to indicate the states of the counter may be easily deduced.

FTGURE 3 is a more detailed block diagram of the input and output circuits of the computer than shown in FIG. l. These circuits control and synchronize data llow between the computer and external devices. There are three cables, respectively cable A, cable ii and cable C, which connect input signals to the computer and remove output signals therefrom. Cable A can have 3() input wires and 30 outpttt wires. Cable B cnn have 30 input wires and 30 output wires. Cable C can have l5 input wires and 15 output wires. The input wires of Cabic A are connected to 3D input amplifiers, represented by the rectangle 202. The cabe B can have 3U input wires connected to 3() input amplifiers, represented by thc rectangle 204. The l5 input wires o? cable C are connected to 15 amplifiers, represented by the rectangle 296.

Fifteen of the input amplifiers of cable A are connected to l5 coincidence gates, represented by the rectangle 112. Under the control of the (TAT logic 114, the 15 gates may be enabled to transfer' their outputs into the T-regis4 ter. The remaining l5 ampliiicr outputs carrying cable A signais are applied to the l5 coincidence gates 2i2. Under control of lClAi. logic 52, these gutes can transfer their' outputs into the E-register.

The output of t5 of the 30 input amplifiers 204 of cable B are connected to l5 gutes 116. Linder control of the CTBT logic and circuits 118, these l5 gates can transfer their outputs into the '.l`-register, Fifteen coincidence gates 5.5, when activated by CIBE logic 54, can transfer the signals on the remaining l5 input amplifiers of cable B into the E-register.

The l5 wires of cable C are amplified by the 15 input amplifiers and appiicd to 15 coincidence gates 57. When ClCE logic circuits 56 activate these gates, their contents can be transferred into the T-rcgister.

The structure of the logic circuits CIAT, CIAE, CBT, (lllx, und (iCl will he inuit: clear stetserpgcnt herein. Computer control signals are generated in response to control signals received from external devices (not shown) which can direct the input-output circuit to connect the computer input channel to one of the three input cables and to connect the computer output channel to one of the output cables. In this manner, the computer may be switched to an inputoutput device, which is thereby prepare-d to receive or transmit data. The transfer of data is always accomplished by word or block logands initiated by the control logic of the computer. Direction of transfer specified by the word or the block logand selects either the input or the output channel. As indicated above, cables A and B can input thirty bits into the T and E- registers, foilowed by a transfer from the T-register to the E-register. Output is from the T and E-registers after transfer from the E-register to the T-rcgister. Cable C always inputs to the E-register and outputs from the T- register.

Iu `addition to the data lines which comprise cable A, cable B, and cable C, each cable will also have at least one control line, respectively designated by 226A, 226B, and 226C, on which external signals can be applied. An external signal, on each line, for example respectively designated by IIDA, IIDB, or IIDC, indicates that a data word is available for input to the computer. Another eX- ternal signal, respectively designated as IODA, IODB, and IODC, indicates that a peripheral device is ready to accept a word of data.

To control the various timing sequences necessary for data inputs and outputs, a three-bit register, called a timing register, is provided. This register is shown in FIG- URE 4. The register is made up of three flip-flop circuits, respectively FCSI, FC52, and FCC53. Flip-flop 53 may be driven to the state wherein its normal output is activated by signals applied thereto through an OR gate 228. Or gate 228 is actuated by the output from either an AND gate 230, and AND gate 232, or an AND gate 234. AND gate 23() provides an output in the simultaneous presence of the complementary output Of iptlop PCSI, and the normal output of ip-tlop FC52. AND gate 232 provides an output in the simultaneous presence at its input of signals CWBI, GAIDR, GACSO, and FNTIC. The method of achieving these signals from basic logic signals is generally represented in FIGURES 2A, 2B, and 2C of the drawings. However, the specic combinations required for producing these signals is set forth in detail in a list of logical equations, which is shown subsequently herein. The PNTIC signal is the complement output of an FNTI (llip-tlop, which is shown in FIG-URE 5.

AND gate 234 provides an output in the simultaneous presence of Signals COUT, DLllN, DODRN, FODRN, FNTOC, and GAC50. The DLllN signal is the normal output of the eleventh ilip-ilop in the `L-register. The FNTOC signal is derived from the complementary output of an FNTO iiip-op shown in FIGURE 5. The FODRN and DODRN signals are the normal signals obtained from the respective DODR and FODR Hip-flops shown in FIGURE 7. The COUTC signals and GACSI] signal derivation will be shown subsequently in the list of logical equations to be provided herein.

FCSS ilip-ilop is driven to provide a complementary output by the output of an OR gate 236. OR gate 236 is driven by the output of either AND gate 238, AND gate 240, or AND gate 242. AND gate 238 is driven in the simultaneous presence of signals FCOIN, FTLDC, and GACS'. AND gate 240 is driven in the simultaneous presence of signals CRHS, and GAC57. AND gate 242 iS driven in response to the simultaneous presence of signals FCOIN and DPOW. The source of the input signals to AND gates 238, 240, and 242, not yet shown, will be shown subsequently herein.

The FC52 flip-Hop is driven to provide a normal output from the output of an OR gate 244. This OR gate may be driven in response to the output of either AND gate 246 or AND gate 248. AND gate 246 provides an 10 output in the simultaneous presence at its input of signals CRI-IS, FSOlC, FTLDN, and GAC51. AND gate 248 provides an output in the simultaneous presence at its input of signals CRI-IS, GAOll, and GACSI.

The FCSZ flip-Hop is driven to provide a complement output signal by the output of an AND gate 250. This AND gate provides an output signal in the simultaneous presence of signals FCSSN and FCSIN.

F C51 ip-op is driven to provide a normal output signal from the output of an OR gate 252. This OR gate is driven by the output of either AND gate 254, 256, or 258. AND gate 254 is driven in response to the simultaneous presence at its inputs of signals FCSSN and FC52N, AND gate 256 is driven in response to the simultaneous presence at its input of signals CWBI, GAIDR, FTLDC, and FNTIN. AND gate 258 is driven in the simultaneous presence of signals COUT, DLlIC, FSOIC, DLOZN, and GACSI).

Flip-tlop FCSI is driven to provide a complement output by the output of an OR gate 260. The OR gate 260 is driven in response to the output of an AND gate 262 or an AND 264, or an AND gate 266. AND gate 262 is driven upon the application to its input simultaneously of the outputs of FCSSC and FC52N. AND gate 264 is driven in response to the simultaneous application to its input of outputs FC53N and FCSZC. AND gate 266 is driven in response to the simultaneous application to its inputs of signals FCOIC and DPOW.

The input and output cables which are selected are determined by the output signals of three flip-flops, respectively FNTI, FNTA, and FNTO. The FNTI ip-op is driven to provide a normal output in response to the output of an AND gate 268. This AND gate has its output energized in the simultaneous presence of signals CIOC, GACHG, and DLO3N. AND gate 270 is ernployed to drive the FNTI llip-op to provide a complenient output. AND gate 270 has its output energized upon the simultaneous presence at its input of the signals CIOC, GACHG, and DLOIC.

The FNTA Hip-flop is driven to provide a normal output signal by the output of an AND gate 272. This AND gate is driven in response to the simultaneous presence of signals CIOC, GACHG, and DLOIN. Flip-ilop FNTA is driven to provide a complement output by the output of an AND gate 274. This AND gate must simultaneously receive signals CIOC, GACHG, and DLOlC in order to drive the FNTA flip-flop. The FNTO dip-flop is driven to provide a normal output in response to output from an AND gate 276. This AND gate is driven in response to the simultaneous presence of signals CIOC, GACHG, and DLOZN. An AND gate 278 drives tiip-ilop FNTO to provide a complement output. This AND gate requires input signals CIOC, GACHG, and DLOZC.

The A cable input and output wires are used for FN- TAN, FNTIN, FNTON signals. FNTAC, FNTIN and FNTON call `for B cable input and B cable output. FN- TAN, FNTIN and FNTOC call for A Cable input and C cable output. FNTIN, FNTAC and FNTOC call for B cable input and C cable output. FNTAN, FNTON and FNTIC call for C cable input and A cable output. FN- TAN, FNTIC and FNTOC call for C cable input and C cable output.

FIGURE 6 is a block diagram of an FTLD {lip-flop whose outputs are used to indicate to the channel-designation register and timing-control register when the T- register is in use. If the T-register is in use, it can be used for further input or output. The FTLD Hip-flop is driven to provide an N-output by the output of an OR gate 280. This OR gate is driven by the outputs of any one of four AND gates, respectively 282, 284, 286, 288, and 290. AND gate 282 is driven upon the simultaneous application to its inputs of signals COUT, DL11N, and FTLDC. The AND gate 284 is driven in response to the application to its input simultaneously of signals CWBI and CIAT. AND gate 286 is driven in response to the application to 11 its input of signals CWBT and ClBT. AND gate 288 provides an output in response to the simultaneous input of signals COUT, DLO-3C, and THT. AND gate 290 providesl an output in response to the application to its input simultaneously of signals COUT. and FCSlN.

The iiip-t'lop FTLD is driven to provide a complement output by the output from an OR gate 292. This OR gate is driven in response to un output from any one of AND gat-:s 294. 296. 29S, and 38). AND gate 296 requires at its input signals DODRC. FODRC, and FNTOC before it provides an output. @iD gate 2% requires at its input simultaneously signals TTE and FCS3N before it can provide an output. AND gate 293 has its output energized in the presence simultaneously of input signals FN'ION and GACS'?. AND gate 301i has its output energized in the simultaneous presence of signals COUT, DLllC. and GACS'T. ln the logical collations to be set forth subsequently herein, the derivation of all these signals applied to actualc the FTLD tlip-ilop` which are not yet shown. will he set tortli. For example, tlic GAC`57 signal is derived trom the simultaneous presence of signals FC53C, FCSZC. and FCSIN. These signals are derived from the timing control register shown in FIGURE 4.

FlGURii 7 isa block diagram of other tiipfiop circuits `which are employed in controlling the input and output data requests. The outputs ol the flip-flops DlDR and l'TlDR are applied to the timing-control register and channel-designation register shown in FIGURES 4 and 5, in response to input and output data-request signals. Flipllop DlDR is driven to provide a normal output hy the output ot' an OR gate 391. This OR gate is driven in response to the output ol either AND gate 302, 304. or 366. The AND gate 302 requires as input signals a data signal HDA, received troni liuc 226A. and TINTIN and FNTAN signals. These are the normal outputs of flip-Hops FNTI and lfNTA, shown in FIGURE 5.

AND gate 304 requires a simultaneous application of input signals llDB, FNTIN, and FNTAC, to provide an output. AND gate 306 requires simultaneous input of signals HDC and FNTlC. Flip-tlop DIDR returns t the state at which it provides a complement output in the ah ence of any input signals. The normal Output of l'lipllop DlDR drives ilipalop FlDR to provide a normal otitpur. The complement output of flip-'flop HDR is obtained in response to an input logand being applied to its reset input'. This input logand consists of signals CWBT and GACS, which are applied to an AND gate 310. The out put of AND gate 31T) can drive an OR gate 308. which in turn can drive the FIDR flip-Hop to provide a complentent output. Another AND gate 312 can also drive OR gate` 388 in response to the application to its input ol `signals CWBI. FSOC. and GACS'T. The DODR llip-ilop is driven to provide a normal output by an OR gate 314. The OR gate 314 is driven in response to outputs from any one of AND gate 316. 318, or 320. AND gate 316 proxides an output in the simultaneous presence of inputs TODA. FNTON, and FNTAN, AND gate 318 provides an output in the presence of simultaneous inputs IODB, FNTON. and FNTAC. AND gate 320 provides an otitput in the simultaneous presence of inputs IODC and FNTOC.

DODR tiipntiop returns to its complement state when no signals are applied from the OR gate 314. The normal output of ilip-ilop DODR drives tiip-op FODR to provide a normal output. lflip-ilop FODR is driven to provide a complement output when an output logand is applied to itsI input through an OR gate 322. OR gate 322 is driven hy either an AND gate 324 or an AND gate 326. The AND gate 324 can he driven in response to the applica tion to its input of signals CWPS. GA012, DL11N. and FNTOC. AND gate 326 can he driven by the application tti its input of signals (TOUT, DLI 1N, and GAFEI.

rthe DlDR. HDR, DOOR and FODR tlip-llops provide output signals to the channel designation and timing 12. control registers as well as to the control logic CIAT, ClAE. ClBl, (lBll, (llE and (lfli.

For handling the output signals trom the F. and T-regis ters 30 output ampliiiers 328 are provided. Tilteen of these receive output iront the Tlregister output gates. and the remaining l5 receive output trom the T-registcr output gates. 'lhe 3d output amplifiers are connected to the 3d output lines of hoth cattle A and cable B. The 15 output amplitiers allocated to the` 'liegister are also connected to the 15 output lines ol canlc t...

Two more flip flops are employed in the input-output control portion of the computer. These are shown in FIGURE 8 and are, respectively, tlip-tlops FIlN and IiDlN. Flip-Hop 1 `DlN provides a normal input when it has been signaled that there is an interrupt routine to he performed hy a signal over a line associated with one of the input cables. The FDIN ilip-llop provides its normal output until the interrupt routine is completed and prevents further recognition ot` any data interrupts during this interval. The lfllN tiip-tlop prevents interruption of the interrupt routine. The lfDlN tlip-liop provides a normal output in response to an input from an AND gate 330. This AND gate requires input signals CHRS, GAOIS, DL13C, and DLOBN before it provides an output. The FDIN iiip-ilop is driven to provide a complement output in response to the output from an AND gate 332. This AND gate is driven in response to signals CWPS, GAOIS, GL13N. and DLOSN.

Flip-flop FUN is driven to provide a normal output in response to the output of an AND gate 334; this AND gate provides an output in response to input signals CRHS, GAOIS, DLISC, and DLO3C. Flipfiop FllN is driven to provide a complement output iu response to the output of AND gate 336; this AND gate provides an output in response to signals CWS, GAOIS, DL13N, and DLOSC.

Sununarizing brietiy, operation of the input-output circuits serves to control and synchronize data liow between computer and external devices. Control signals from the external devices together with computer control signals direct the selection of which of three input cables are selected for data input and which of three output cables are selected for data output. Input data requests are applied to flip-flops PIDR and DIDR and are thence corumunicated to the timing counter FCSLFCSS and 1iip Hops FNTA, FNTl and FNTO together with logand signals from the computer to open the gates which select the cables. Output data requests are applied to tiip-tlops FODR and DODR and are thence communicated to the timing counter FC51FC53 and tiip-flops FNTA, FNT and FNTO together with logand signals from the computer to open the gates which select the cables.

Reference is now made to FIGURE 9, which shows a block diagram of the `arrangement employed for addressing the core memory from either the L-register or the M-register. The determination as to which of these addresss controls is the function allocated to the output of a ilipiiop designated as FZOO. This iiipflop provides a normal outuput in response to the application of signals CWLAN, DFOAC, and DEO7N, which are applied to an AND gate 340. The output of this AND gate is applied to the FZOO hiphop. Another AND gate 342 can drive this ilip-llop to provide a complement output in response to the simultaneous application to its input of signals CWTA, DLISN, CWIS, DLMN, and CWPA.

The address outputs from the luf-register are applied to X-drive-line address-selection logic 344. The selected address-output line connects to an AND gate 346. This AND gate provides an output when it receives a PZOOC signal from the llipdlop FZOO. The L-register address outputs are also applied to X'drive-line address-selection circuits 348. The selected X-line address is applied to an AND gate 35i). which has as its other required input un output trom the l'YOON side ol` the iiip-ilop F700. The outputs of AND gate 3156 and 350 are applied to an OR gate 352. The OR gate output is applied to a driving AND gate 354. This AND gate is enabled to drive the core memory selected X-line for reading from a reading-timing generator 456 or for writing from a Writingtiming generator 358. The reading-timing generator is driven by the output of an AND gate 360, which response to signals CACT and FSOZN, The Writing-timing generator responds to the output of an AND gate 362, which provides an output when the timing signals CACT and FSOZC are applied to its input.

Two Y-drive-line address-selection circuits, effectively 364 and 366, are provided. The Y-drive-line address-selection circuits are addressed from the M-register and the selected address is applied to an output AND gate 368. This AND gate is enabled in the presence of the FZOOC signal. The Y-drive-line address-selection circuits 366 are addressed from the L-register. The output is applied to an AND gate 370. This AND gate is enabled in the presence of the FZOON signal from the flip-flop. The output of AND gates 368 and 370 are applied to an OR gate 372. The OR gate output is applied to an AND gate 374. This AND gate is driven in response to the output of the OR gate 372, and signals from either the read-timing generator 356 or the write-timing generator 358. The AND gate 374 output drives the selected Y- lines to the core memory 380.

It was described previously herein that the coincidence of the X- and Y-drives cause a core in each core plane to be driven. A sense line threaded through each core plane detects whether the output of the driven core is a P or an N signal. The sense lines are connected to read amplifier 380. The output of each one of the read amplifiers is applied to an AND gate 382. Strobing-pulse logic 389 enables these AND gates 382 to transmit the signal applied to their inputs at a time which is determined by the logic shown in FIGURE l2. This interval is selected in order to minimize the effect of any stray signals which can give a false reading signal. The output of the gates 382 is applied to the E-register to drive the delay flip-flops DE01 through DE15 therein to states representing the information read out of the core memory.

The E-register output is applied to inhibit drivers 384. These inhibit drivers are enabled to drive inhibit lines in the presence of an output from an AND gate 386. This AND gate is enabled by logic signals CACT and FSOZC being applied to its inputs. Each one of the inhibit lines is threaded through an entire core plane of the memory 380. The address of the data which has been read into the E-register is again applied to the respective X- and Y-drive-line selection circuits, which drive the selected X and Y lines in a direction so that the core at each core plane coupled to the driven X and Y lines will be driven to one of its states of remanence. This will occur except in those core planes in which an inhibit line is excited. This excited inhibit line will prevent the core from being driven by the X and Y drive lines.

Accordingly, in the foregoing description, it has been shown that the M- or L-register can address the memory, as determined by the output of the FZOO flip-flop. As soon as data has been read out of the core memory into the E-register, it is read back into the core memory to restore the logand which, in the process of reading, has been destroyed.

FIGURE 12 is a block diagram of the strobing-pulse logic 389. A strobing-pulse generator 390 is enabled to produce a strobe-pulse output upon receiving an energizing signal from an AND gate 392. rThe AND gate receives the output of an OR gate 394 at its input, as well as signals CACT and FSOZN. The OR gate 394 is enabled by the output of any one of AND gates 396, 398, 400. and 492. AND gate 396 can provide an output in the simultaneous presence of signals CWLAN, DE14C, DEIZC, and DEOQC. AND gate 398 can produce an output in the simultaneous presence of signals CWLAN,

14 DEISC, DE14C, and DE13C. AND gate 400 can produce an output in the simultaneous presence at its input of signals CWIAN and GAOOS. AND gate 402 can produce an output upon the simultaneous application to its input of signals CWPSN, GAO19, and GAOO9.

It has been indicated herein that each one of the L, M, P, E, A, T registers contains fifteen delay flip-hops. FIG- URE 10 is a block diagram of a typical delay flip-flop and its associated logic. The delay Hip-flop 404 can comprise any well known Hip-flop circuitry which has two inputs, respectively set and reset, and has two stable states. In response to an input applied to its set terminal, it will transfer, after a short delay, to one of the stable states at which it provides an N or normal output. In response to an input applied to its reset terminal, it applies a C" or a complement output. An AND gate 406 drives the delay flip-flop to provide an "N output upon receiving a clock pulse from the clock-pulse generator of the computer and also a signal from the output of any one of the computer logic gates which drive this flip-flop.

AND gate 204 output is applied to the set input terminal of the delay Hip-flop, and also is applied as an inhibit input to a gate 408. Another input to gate 408 is the output of the clock-pulse generator. The output of the gate 408 is applied to the reset terminal of the delay llipilop. In the presence of a signal from the computer logic gates and a clock pulse, the Output of AND gate 406 drives the delay flip-flop to provide a normal output and inhibits gate 408 from passing the clock pulse. When no signal is received from the logic gates of the computer, but a clock pulse is received, then the clock pulse is applied through gate 408 to the reset input of tbe delay flipop which is reset so that it provides a complement output. Accordingly, in the embodiment of the invention, the registers can change their contents on each clock pulse, unless instructed to the contrary.

FIGURE 1i is a block diagram illustrating a typical logic controlled transfer of the type which is employed herein for transfers between the various registers. There is shown by way of example a transfer from the E- register to the I -register and from the L-register to the E- register. The N-output of each delay flip-flop in the L- register is applied to a diiferent one of 15 gates. These are represented by the TLE rectangle 410 (transfer from L to E-rcgister). Each one of these 15 gates applies its output to a different one of the gates 406 (shown in FIG. 10) of the 15 delay flip-flops in the E-register 14. The TLE gates 410, however, are not able to transfer the L-register outputs until an enabling signal is received from an OR gate 412. This OR gate can apply the required output in the presence of an input from any one of AND gates, respectively 41.4 or 416. The AND gate 414 provides an output in the simultaneous presence of input signals CWLAN (see FIGURE 2B) and the ninth, twelfth, and fourteenth stage complement outputs of the E-register. AND gate 416 can provide an output in the simultaneous presence of input signals CWLAN, CACT, GAFI., and CSHFN. The GAFL signal is derived by applying the complement outputs of the eleventh, twelfth, and thirteenth stages of the L-register to an AND gate 418. The output CSHFN is derived from signals FOOIN, FSO3N, FSOZC, DLISC, DLI-4N and DL10N being applied to an AND gate 420. AND gates 418 and 420 have their outputs applied to AND gate 416.

The transfer of the contents of the L-register to the E- register can be represented by the following logical equation:

In the equation provided, the symbolism is that commonly employed in logic equations. The joins the and terms and the i joins the or terms.

A transfer of the contents of the E-register into the L- 

1. IN A DATA PROCESSING SYSTEM HAVING A MEMORY INCLUDING A PLURALITY OF LOCATIONS EACH RESPECTIVELY STORING EITHER AN INSTRUCTION OR A DATA WORD; A PLURALITY OF REGISTERS; MEANS FOR SELECTIVELY ACCESSING ONE OF SAID INSTRUCTION WORDS FROM SAID MEMORY AND FOR STORING SAID INSTRUCTION WORD IN A FIRST OF SAID REGISTERS; MEANS FOR IDENTIFYING A FIRST DATA WORD STORED IN SAID MEMORY; MEANS FOR ACCESSING SAID FIRST DATA WORD FROM SAID MEMORY; MEANS FOR STORING A TEST DATA WARD IN A SECOND OF SAID REGISTERS; 